<div dir="auto"></div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">---------- Forwarded message --------- From: Abimathi Natarajan <<a href="mailto:abimathi08@gmail.com">abimathi08@gmail.com</a>> Date: Thu, Feb 7, 2019, 6:27 PM Subject: Re: [cairo] cairo_paint() with GPU Buffer To: Uli Schlachter <<a href="mailto:psychon@znc.in">psychon@znc.in</a>> </div> <div dir="ltr"><div dir="auto">Hi, My sample code contains two parts, PART 1------------ <ul style="margin-bottom:0px;margin-top:0px"><li>Decoding an input file using ffmpeg and get raw buffers (GPU allocated within FFMPEG ) in rgb32 format. My code does exactly what the below ffmpeg command does. </li></ul> <pre class="m_8221002412132779190gmail-x_wiki"> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i input.mp4 -vf 'scale_vaapi,hwmap=mode=read+write+direct,format=rgb32' output.rgb The above command will decode the input file (input.mp4) with hardware accelerations(vaapi) and hwmap will directly map the hardware frames to system memory. </pre><pre class="m_8221002412132779190gmail-x_wiki">PART 2 ---------- </pre> <ul style="margin-bottom:0px;margin-top:0px"><li>I will directly feed this memory to </li></ul> <pre class="m_8221002412132779190gmail-x_wiki"><div> cairo_image_surface_create_for_data ((unsigned char *)buffer, CAIRO_FORMAT_ARGB32,width, height, stride) to create a cairo_surface for the given frame.</div><div><ul style="margin-bottom:0px;margin-top:0px"><li> cairo_paint() in <a href="https://github.com/wayland-project/weston/blob/master/clients/image.c#L160" rel="noopener noreferrer noreferrer" class="m_8221002412132779190gmail-x_OWAAutoLink" id="m_8221002412132779190gmail-LPlnk875368" target="_blank">https://github.com/wayland-project/weston/blob/master/clients/image.c#L160</a> will paint the cairo_surface over weston compositor. </li><li>When we measured the time taken by this API to paint the GPU buffer, we observed it took approximately 400 ms to paint a single 4k frame.</li><li>The github link is not my actual sample code, However my application uses similar flow only. (I'm using cairo with weston compositor).</li></ul><div> </div></div><div> </div></pre></div></div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Feb 6, 2019, 12:40 AM Uli Schlachter <<a href="mailto:psychon@znc.in" target="_blank" rel="noreferrer">psychon@znc.in</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi, On 05.02.19 07:16, Abimathi Natarajan wrote: > I'm implementing a sample program with Weston to render video (decoded > using ffmpeg VAAPI) frames using Cairo graphics. > Each frame is of 4k size How complicated is your example program? Do you have a link to it or can you send it by mail? > I'm passing GPU buffer directly to cairo_image_surface_create_for_data() to > create a cairo_surface for each frame. > When I render the buffer using cairo_paint() , the API is taking > approximately 400 ms for each buffer. Uhm, can you tell us more about the cairo_paint() call? I assume you are copying from the image surface that you created. Where are you copying to? Is it just the call to cairo_paint() that takes so long or did you measure more than just that? Also, what exactly does "I'm passing GPU buffer directly" mean? Is the GPU memory directly accessible to the CPU? If so, I would expect this to be uncached and slow, which is why I am asking. Cheers, Uli -- Homophobia - The fear that another man will treat you the way you treat women. </blockquote></div> </div>